A test of conditioned taste aversion with mouse interferon-alpha

Interferon-alpha treatment induces anorexia in cancer patients and in mice. The ability of interferon-alpha to induce a conditioned taste aversion (CTA) in mice was explored. Mice were injected with doses of interferon-alpha that had been shown to induce anorexia (M. A. Segall & L. S. Crnic, Behav. Neurosci., 1990; 1600 or 800 U/g of mouse) after being given a novel solution (chocolate milk). Neither dose of interferon resulted in a decrease of milk intake on the test day. To determine whether the known cognitive effects of interferon interfere with the ability of a mouse to learn CTA, a combined injection of interferon-alpha and LiCl (an illness-inducing agent) was given. The combination of interferon-alpha with LiCl did not interfere with the LiCl-induced CTA. Thus, any possible cognitive effects of interferon did not interfere with conditioned taste aversion. To test the possibility that repeated trials might establish a conditioned taste aversion to interferon, mice were given three conditioning trials spaced 3 days apart. No aversion developed. Doses of interferon-alpha that produce anorexia do not produce a conditioned taste aversion, indicating that separate mechanisms are activated in these two behaviors.